Conferences - Seminars
EESS talk on "Catchment storage, chemical dynamics, and hydrological response, on timescales from minutes to months"
By Dr James W. Kirchner, Professor of Physics of Environmental Systems, Environmental Systems Science, ETH Zurich and Director, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) is a physicist by training, James Kirchner has worked in fields ranging from hydrology, aqueous geochemistry, and geomorphology to evolutionary ecology and paleobiology. Much of his current work focuses on the flow, chemistry, and geomorphology of mountain streams. Dr. Kirchner received his bachelor's and master's degrees from Dartmouth College, and his Ph.D. from the University of California, Berkeley. He was a member of the Berkeley faculty from 1991 through 2010, most recently as Goldman Distinguished Professor for the Physical Sciences and Director of Berkeley's Central Sierra Field Research Stations. From 2007 to 2012 he served as Director of the Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), where he supervised a scientific staff of 550, and where he remains as a senior scientist. He is currently Professor for the Physics of Environmental Systems at ETH Zurich, the Swiss federal technical university. He became a Fellow of the American Geophysical Union in 2008. He was the European Geosciences Union's 2013 Ralph Alger Bagnold Medalist and the American Geophysical Union's 2016 Langbein Lecturer.
Landscapes are characterized by preferential flow and pervasive heterogeneity on all scales. They therefore store and transmit water and solutes over a wide spectrum of time scales, with important implications for contaminant transport, weathering rates, and stream chemistry. Catchment transit time distributions are nonstationary, reflecting fluctuations in precipitation forcing, heterogeneity in catchments themselves, and nonlinearity in the mechanisms controlling subsurface storage and transport. The challenge of empirically estimating these nonstationary transit time distributions in real-world catchments, however, has only begun to be explored.
In the past, chemical tracers and stable isotopes of water (18O and 2H) have been widely used to separate event-scale hydrographs into "new" and "old" water, based on short-term intensive isotope sampling campaigns focused on individual storm events. We have recently developed and deployed a "lab in the field", in which stable isotopes and major ions in precipitation and streamflow are measured automatically at hourly or sub-hourly resolution, for months at a time. These measurements create new opportunities to study how rainfall becomes streamflow on timescales of minutes to months following the onset of precipitation. In this talk I will introduce these new data streams, as well as new tools that can be used to infer catchment storage dynamics and hydrologic response.
Organization EESS - IIE
Contact Prof. Andrea Rinaldo and Dr Paolo Benettin, ECHO
Accessibility General public
This event is internal